Detergent composition

ABSTRACT

DETERGENT COMPOSITIONS CONTAINING SODIUM NITROLOTRIACETATE, PEROXY-COMPOUNDS, AND ALKALI-METAL SALTS OF MONO- AND DIHYDROXAMIC ACIDS, ARE DISCLOSED. THE HYDROXAMIC ACID SALTS ARE EFFECTIVE INHIBITORS AGAINST THE CORROSION OF COPPER AND ITS ALLOYS BY AQUEOUS SOLUTIONS OF SUCH DETERGENT COMPOSITIONS.

United States Patent ABSTRACT OF THE DISCLOSURE Detergent compositions containing sodium nitrilotriacetate, peroxy-compounds, and alkali-metal salts of monoand dihydroxamic acids, are disclosed. The bydroxamic acid salts are effective inhibitors against the corrosion of copper and its alloys by aqueous solutions of such detergent compositions.

The present invention relates to detergent compositions, particularly fabric-washing detergent compositions, comprising alkali-metal salts of nitrilotriacetic acid and peroxy-compounds, notably alkali-metal pgrbggajes, and percarbonates. In partic re ates to such compositions containing an additive to inhibit or reduce the corrosion of copper and its alloys that can arise from the use of these compositions.

Hitherto it has been conventional to use as detergency builders in detergent compositions various alkali-metal phosphates, in particular sodium tripolyphosphate. However, as it has been suggested recently that the use of such phosphates in detergent compositions may be a factor contributing to the phenomenon of eutrophication, the possibility of using non-phosphate metal-chelating compounds as detergency builders is being considered. It is 'known that other metal-chelating compounds, notably the alkali-metal salts of nitrilotriacetic acid, can build detergency to an extent approaching that of the conventional phosphates. However, it has been observed that when these non-phosphate metal-chelating compounds are employed in detergent compositions that also comprise peroxycompounds, severe corrosion of copper and copper bearing alloys that come into contact with aqueous solutions of these compositions results. This constitutes a serious disadvantage with respect to the use of these compositions, particularly for fabric washing, as many presently-available domestic washing-machines utilise copper and its alloys in their construction, and certain components of these machines are thereby subject to severe attTck during the washing process.

Numerous conventional anti-tarnishing and anti-con rosion agents have been proposed as inhibitors for this copper corrosion, but generally their performance in this respect has been found to be inadequate due to the severity of attack suffered by copper in the presence of these particular compositions. The most successful of these proposed inhibitors are triazoles such as benzotriazole and bis methylene benzotriazole, ethoxylated phosphate esters, and oximes such as benzoin-a-oxime, but even these materials have been found for various reasons to be disadvantageous in certain respects. Certain of these proposed inhibitors impart undesirable discoloration to aqueous solutions of the compositions in which they are incorporated, or are unstable and therefore require to be protected by, for instance, being encapsulated or incorporated in soap noodles, to prevent their decomposition during storage. Those inhibitors which tend to be unstable cannot therefore be subjected to heat, such as would occur during, for example, spray-drying, and hence must be incorporated into detergent compositions by separate dosing. Also, the manufacturing costs of some of these inhibitors are such that to incorporate them in a detergent Patented Dec. 26, 1972 composition at a level sufficient to achieve adequate corrosion inhibition is economically unattractive. I

By the present invention it has been found that copper corrosion by aqueous solutions of detergent compositions comprising one or more alkali-metal salts of nitrilotriacetic acid and one or more peroxy-compounds, can be considerably reduced by the incorporation of one or more alkali-metal salts of certain hydroxamic acids into these detergent compositions.

The present invention provides a detergent composition comprising a detergent active agent, an alkali-metal salt of nitrilotriacetic acid, a peroxy-compound, and, in an amount from about 0.1 to about 20% by weight of the peroxy-compound, an alkali-metal salt of a hydroxamic acid, which hydroxamic acid has one of the formulae:

R CONHOH RzCH-CONHOH Rr-CH-CHr-CONHOH ONHOH ONHOH essential feature of the invention. The detergent active agent or agents may be anionic, nonionic, cationic or amphoteric in character, and mixtures of these different types of detergent active agents can be used. Examples of these detergent active agents are:

(a) Anionic detergent active agents: soaps, i.e. alkalimetal, preferably sodium and potassium, salts of longchain fatty acids Mg from 8 to 22 carbon atoms, such as lauric, myristic, oleic palmitic, capric, caprylic and stearic acids, either as singly or in complex mixtures of differing chain length, derived either from the saponification of natural fats and oils, such as tallows, coconut oil, palm oil, palm kernel oil, groundnut oil, tall oil and babassu oil, or by synthetic means; alkali-metal salts of organic sulphuric reaction products having in their molecular structure an alkyl radical containing from.

abouhfito about 22 carbon atoms and a radical selected from the groupconsisting of sulphonic acid and sulphuric acid ester radicals (included in the term alkyl is the alkyl portion of higher acyl radicals) such as sodium or potassium alkyl sulphates, preferably those obtained by sulphating the higher alcohols (C -C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene-sulphonates in which the alkyl groupcontains from about 9 to about 20 carbon atoms and in which the alkyl group is attached to, the benzene ring in either the 1 position or at the secondary positions, such as in sodium linear alkyl (C -C secondary benzene sulphonate, Z-phenyl-dodecane-sulphonate, Z-phenyl-octadecanesulphonate and 3-phenyl-dodecanesulphonate; alkali-metal, preferably sodium, olefin sulphonates, i.e. the mixture of detergent active agents obtained when the products of the sulphonation of C -C olefins, preferably substantially straight-chain alphaolefins, are neutralised and hydrolysed completely or almost completely; sodium alkyl glyceryl ether sulphonates, especially those ethers of the higher alcohols derived from tallow coconut oil and synthetic alcohols derived from petroleum; sodium coconut oil fatty acid monogiyceride sulphates and sulphonates; sodium or potassium salts of splphur acid esters of the reaction product of one mole of a higher fatty alcohol (e.g. tallow or coconut oil alcohols) and about 1 to 6 Bibles of ethylene oxide per molecule and in which the alkyl radicals contain about 9 to about 18 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralised with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; and sodium or potassium salts of fatty acid amides of methyl taurine in which the fatty acids, for example, are derived from coconut.

(b) Nonionic synthetic detergent active agents: compounds formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol; the polyethylene oxide condensates of alkyl-phenols, e.g. the condensation products of alkyl-phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to to 25 moles of ethylene oxide per mole of alkyl-phenols (the alkyl substituent in such compounds may be derived from polymerised propylene, diisobutylene, octene, dodecene, or nonene, for example); those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylenediamine, such as compounds containing from about 40% to about 80% polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said hydrophobic base having a molecular weight of the order of 2,500 to 3,000; the condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g. a coconut alcohol-ethylene oxide condensate having from 6 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms; long chain tertiary amine oxides corresponding to the following general formula, R R R N O, wherein R is an alkyl radical of from about 8 to 18 carbon atoms and R and R are each methyl, ethyl or hydroxy ethyl radicals, such as dimethyldodecylamine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide and dimethylhexadecylamine oxide, N-bis (hydroxyethyl) dodecylamine oxide; long chain tertiary phosphine oxides corresponding to the following formula 'RR'R"P- O, wherein R is an alkyl, alkenyl or monohydroxyalkyl radical ranging from 10 to 18 carbon atoms in chain length and R' and R" are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms, such as dimethyldodecylphosphine oxide, dimethyltetradecylphosphine oxide, ethylmethyltetradecylphosphine oxide, cetyldimethylphosphine oxide, dimethylstearylphosphine oxide, cetylethylpropylphosphine oxide, diethyldodecylphosphine oxide, diethyltetradecylphosphine oxide, bis (hydroxymethyl) dodecylphosphine oxide, bis (Z-hydroxyethyl) dodecylphosphine oxide, 2 hydroxypropylmethyltetradecylphosphine oxide, dimethyloleylphosphine oxide, and dimethyl-2-hydroxydodeeylphosphine oxide; and dialkyl sulphoxides corresponding to the following formula, RRS- 0, wherein R is an alkyl, alkenyl, betaor gammamonohydroxyalkyl radical or an alkyl or betaor gammamonohydroxyalkyl radical containing one or two other oxygen atoms in the chain, the R groups ranging from 10 to 18 carbon atoms in chain length, and wherein R is methyl, ethyl or alkylol; such as dodecyl methyl sulphoxide, tetradecyl methyl sulphoxide, S-hydroxytridecyl methyl sulphoxide, Z-hydroxydodecyl methyl sulphoxide, 3-hydroxy-4-decyloxybutyl methyl sulphoxide, 3-hydroxy- .4-dodecyloxybutyl methyl sulphoxide, 2-hydroxy-3-decyloxypropyl methyl sulphoxide, 2-hydroxy-3-dodecyloxypropyl methyl sulphoxide, dodecyl ethyl sulphoxide, 2- hydroxydodecyl ethyl sulphoxide, dOdecyl-Z-hydroxy ethyl sulphoxide.

(c) Ampholytic synthetic detergent active agents which are derivatives of aliphatic secondar and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, such as sodium- 3 dodecylaminopropionate, sodium 3-dodecylaminopropanesulphonate and sodium N-Z-hydroxydodecyl-N- methyl-taurate.

(d) Zwitterionic synthetic detergent active agents, namely derivatives of aliphatic quaternary ammonium compounds, sulphonium compounds and phosphonium compounds in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, such as 3 (N,N dimethyl-N-hexadecylammonio) propane-1- sulphonate, 3 (N,N dimethyl-N-hexadecylammonio)-2- hydroxypropane-l-sulphonate, 3-(dodecylmethylsulphonium) propane sulphonate, and 3-(cetylmethylphosphonium) ethane sulphonate.

Further examples of non-soap detergent active agents commonly used in the art are given in Surface Active Agents, Volume 1 by Schwartz and Perry (Interscience 1949) and Surface Active Agents, Volume 2 by Schwartz, Perry and Berch (Interscience 1958).

The alkali-metal salt of nitrilotriacetic acid is preferably the sodium salt, although the potassium salt can be used if desired. The alkali-metal salt of the nitrilotriacetic acid will generally comprise from about 5 to about 50%, preferably from about 10 to about 40%, by weight of the detergent composition. The alkali-metal salt of the nitrilotriacetic acid can make up the whole detergency builder content of the detergent composition, or alternatively it can be one of a plurality of detergency builders present in the composition. Alkali-metal salts of nitrilotriacetic acid are compatible with all conventional detergency builders, and examples of these are:

(a) Inorganic detergency builders such as sodium silicate, sodium metasilicate, We, sodium bicarbonate, sodium tripolyphosphate, triso rum orthophosphate, sodium pyrophosphate and sodium hexametaphosphate;

(b) Organic detergency builders such as sodium and potassium ethylenediaminetetraacetate, and polyelectrolytes, i.e. polycarboxylic acids derived from the polymerisation of unsaturated carboxylic acids and unsaturated carboxylic acid anhydrides, such as maleic acid, acrylic acid, itaconic acid, methacrylic acid, crotonic acid and aconitic acid, and the anhydrides of these acids, and also from the copolymerisation of the above acids and anhydrides with minor amounts of other monomers, such as vinyl chloride, vinyl acetate, methyl methacrylate, methyl acrylate and styrene. Each of the above acids and anhydrides can also be made to copolymerise with a minor amount of one of the other acids and anhydrides named above. These polyelectrolyte detergency builders are generally incorporated in detergent compositions as their alkali-metal salts. Their sodium salts are preferred, although their potassium salts can also be used.

-An alkali-metal salt of nitrilotriacetic acid may be mixed with one or more of the above detergency builders in any proportions. In general, the total detergency builder content of a detergent composition of the invention will be from about 10 to about 50% by weight.

A detergent composition of the invention will incorporate one or more peroxy-compounds, generally in an amount from about 5 to about 40% by weight of the composition. Examples of suitable preferred peroxy-compounds are sodium perborate, potassium perborate and sodium percarbonate. Other peroxy-compounds that may be included in detergent compositions are zinc peroxide; barium peroxide; calcium peroxide; magnesium peroxide; the sodium, potassium, lithium and ammonium salts of the peroxyphosphates of orthophosphoric, pyrophosphoric and tripolyphosphoric acid; the peroxyhydrates of sodium sulphate and potassium sulphate; the sodium, potassium,

lithium, calcium, magnesium and ammonium salts of the peroxyhydrates of alpha-amino phosphoric acids; and the hydrogen peroxide addition products of urea, biuret and amides.

A detergent composition of the invention will contain one or more alkali-metal salts of one or more hydroxamic acids, which can be monohydroxamic acids of Formula I below, 1,1-dihydroxamic acids of Formula II below, or 1,2-dihydroxamic acids of Formula III below:

m-coNnoH 1 RzCH-CONHOH ONHOH II ni-cn-onz-connou UONHOH 111 wherein R is a C to C preferably C to C hydrocarbyl group and R is a C to C preferably C to C hydrocarbyl group. The preferred alkali-metal is sodium, and, less preferably, potassium.

These hydroxamic acids can be readily described with reference to the carboxylic acids from which they are derived. (They may be prepared by reacting hydroxylamine with the required carboxylic acid in methanol, the alkali-metal salt being formed by the addition of the appropriate alkali-metal methoxide.)

The hydrocarbyl groups of R and R, can be alkyl, alkenyl, alkaryl or aralkyl in character. It is preferred that R; and R, are substantially straight-chain alkyl or alkenyl groups, and it has been found that alkali-metal salts of hydroxamic acids derived from bleached tallowclass fatty acids are particularly suitable for use in detergent compositions of the invention. Examples of suitable monohydroxamic acids are, for instance, those derived from lauric (dodecanoic) (R is C tridecanoic, myristic (tetradecanoic), pentadecanoic, palmitic (hexadecanoic), margaric (heptadecanoic), stearic (octadecanoic) and arachidic (eicosanoic) acids, and from lauroleie (cis-9-dodecenoic), physeteric (S-tetradecenoic), myristoleic (cis-9-tetradecenoic), palmitoleic (cis-9-hexadeeenoic), petroselinic (cis-fi-octadecenoic), petroselaidic (trans-6-octadecenoic), oleic (cis-9-octadecenoic), elaidic (trans-9-octadecenoic), vaccenic (trans-ll-octadecenoic) and gadoleic (cis-9-eicosenoic) acids. Monohydroxamates of other acids that may be used are, for example, linoleic, linolelaidic, hiragonic, alpha-oleostearic, beta'oleostearic, pumicic, linolenic, elaidolinolenic, pseudooleostearic, moroctic, alpha-parinaric, beta-paranaric, arachidonic, dehydroundecylenic, tariric, stearolic, ricinoleic and licanic acids. Particularly suitable are monohydroxamic acids deriveififrom the complex mixtures of saturated and unsaturatedfatty acids derived from natural fats, such as tallows, coconut oil, palm oil, palm kernel oil, babassu oil and groundnut oil.

Examples of 1,1-dihydroxamic acids suitable for use in the invention include those derived from dicarboxylic acids such as undecane-l,1-dicarboxylic (R, is C dodecane-l,l-dicarboxylic, n'idecane-Ll-dicarboxylic, tetradecane-l,l dicarboxylic, pentadecane-1,l-dicarboxylic, hexadecane-l,1-dicarboxylic, heptadecane-l,l-dicarboxylic, octadecane-l,l-dicarboxylic and nonadecane-l,l-dicarboxylic acids. Analogous unsaturated acids can also be used.

Examples of 1,2-dihydroxamic acids suitable for use in the invention include those derived from dicarboxylic acids such as dodecane-l,2-dicarboxylic (R, is Cm), tridecane-l,2-dicarboxylic, tetradecane 1,2 dicarboxylic, pentadecane-1,2-dicarboxylic, hexadecane-l,2-dicarboxyl-- ic, heptadecane-l,Z-dicarboxylic, octadecane 1,2 dicarboxylic, nonadecane-LZ-dicarbOxylic and eicosane-1,2-dicarboxylic acids. Analogous unsaturated acids can also be used.

These alkali-metal hydroxamic acid salts are largely free from the undesirable properties of the hitherto proposed corrosion inhibitors, and are effective over a wide range of powder concentrations and in water of all commonly-encountered degrees of hardness. They do not impart undesirable discolorations to the compositions in which they are incorporated, and their stabilities are such that they do not require to be protected or coated in the compositions and they c b6 p rated into the compositions by, for instance, being added to aqueous slurries of the compositions prior to spray-drying.

The amount of the alkali-metal hydroxamic acid salt or salts required in a detergent composition of the invention will depend on the amount of the alkali-metal nitrilotriacetate and the peroxy-compound present, as an aqueous solution of a detergent composition containing a high level of these last two ingredients will be particularly corrosive to copper. A detergent composition of the invention should contain from about 0.1 to about 20%, preferably from about 0.25 to about 5%, by weight of the amount of the peroxy-compound present, of the alkali-metal hydroxamate.

In addition to the essential detergent active agents, peroxy-compounds, detergency builders and hydroxamates described above, a detergent composition of the invention can comprise any conventional detergent composition ingredients, such as lather boosters, for example, alkanolamides like coconut ethanolamide and palm kernelethanolamide; fillers, for example sodium sulphate; antiredeposition agents, for example sodium carboxymethylcellulose; fluorescers; pigments; germicides; perfumes; chemilluminescers; and enzymes.

A detergent composition of the invention can be prepared by any of the conventional manufacturing techniques used in the production of detergent compositions, such as slurry-making and spray-drying, and a detergent composition of the invention can be made in any of the common physical forms associated with detergent compositions, such as powders, flakes, granules, noodles, cakes, bars and liquids.

The invention is further illustrated by the following examples.

EXAMPLES 1-5 Five sodium hydroxamates were compared with three conventional corrosion inhibitors by incorporating the inhibitors at a level of 1% by weight in eight samples of a detergent powder having the following constitution:

Components: Parts by weight Detergent active compound 1 9 Detergent active compound 2 2 Coconut monoethanolamide 0.5

Sodium nitrilotriacetate 15 Sodium tripolyphosphate 10 Anhydrous alkaline sodium silicate 8 Sodium sulphate 26 Fluorescers 0.4 Sodium ethylene diamine tetraacetate 0.1 Sodium perborate 20 Corrosion inhibitor 3 1 Water to 100.

1 A sodium alkyl benzene sulphonate (Sul honated DOB P0. obgzgned frfm 1the Fig-(($181): Chemlfitl Comtihny).

nony p we non o c active sold und th trade name Triton CF21 by Rohm and Haas. er 8 'Example 1-sodium tallow hydroxamate.

Example 2-sodium pentadecane carboxylic acid hydroxa- The corrosion rates of Examples 1 and A-D were determined by the following procedure.

Aktiebolag.

A copper disc of 5 cm. diameter was polished with 600 emery paper, degreased, rinsed, dried and weighed. The disc was then mounted on a PTFE shaft and rotated at 60 r.p.m. in 700 ml. of an aqueous solution of the powder, the water used in each test having a hardness of 4 H. The solution was heated from room temperature (20 C.) to 100 C. in 30 minutes, and maintained at 100" C. for 45 minutes. The change in weight of the disc was recorded, and the corrosion rate determined in gm. m7". hrr In all the following tabulated results, a corrosion rate of less than 0.10 gm. mr' hrr is signified by a dash The powder samples were each used at concentrations of 0.2% and 0.80 by weight in the aqueous solutions, and the following corrosion rates were obtained.

As can be seen from Table I, the powder of Example 1, comprising a hydroxamate, showed the least tendency to attack copper. The only inhibitor of which the efficiency approaches that of the hydroxamate was benzoin-alphaoxime (Example A), but this inhibitor is known to be unstable and deteriorates on storage, thereby requiring to be protected in some way.

The performances of several different hydroxamates as corrosion inhibitors were compared by subjecting the powders of Examples l-5 to the test procedure described above. Water of H and 4 H hardness was used, and the results obtained were as recorded in Tables II and III below.

TABLE II Corrosion rate in 0 H water o. 20 o. 15 4. 9 0. 20 0. l 0. 25 6. 0 0. l5 0. l0 0. 15 6. 2 0. 90 2. 90 0. 25 0. l0 5. 7

TABLE III Corrosion rate in 4 H water Example 1 2 3 4 5 D Powder concentration:

0. n--- 0.10 0.10 4.6 0.4 1.. 6. 0 0.6 0. 0. Z) 0. 10 6. 3 0.8? 0.70 4. 0 0. l5 6. 0

EXAMPLES 6 AND 7 The corrosion-resisting properties of sodium tallow hydroxamate over a wide range of water hardness and pow- 70 7' der concentration was demonstrated using the hydroxamate incorporated at two different percentage levels into two blown detergent powders having the following final constitutions. The hydroxamate was added to the aqueous base powder slurn'es before blowing- Parts by weight Example 6 Example 7 Components Sodium dodeeyl benzene sulphonate 1 Coconut monoethanolarnjde Sodium ta-Ilow sulphate qodium nitriloacetate Godium carboxymethyl cellulose. Fluorescers Sodium ethylenediaminetetmaeetate olourants Sodium sul hate Sodium tai ow hydroxamate... Sodium perborate Water to l Sulphonated DOB 055,. obtained from Shell.

TABLE IV Corrosion rate in 0 H water Powder concentration, percent 0.8

Example:

TABLE V Corrosion rate in 4 H water Powder concentration, percent 0.8

Exagiple:

1Z1IIIIIIIIIIIIIIIIIIIIIIIIIIIII TABLE VI Corrosion rate in 24 H water Powder concentration, percent 0.8

As can be seen from the above tables, the formulations of Examples 6 and 7 showed, over a very wide range of powder concentration and water hardness, little tendency to corrode copper.

EXAMPLES 8-l1 Four detergent powders having the same formulation as the detergent powders used in Examples l-5, and incorporating a corrosion inhibitor of the invention at a level of 1% by weight, were prepared by conventional slurrymaking and spray-drying techniques.

Corrosion inhibitor 8--. Sodium undecane carboxylic acid hydroxmate. 9... Disodium undecane-l,l-dicarboxylic acid hydroxamate. r. 10--. Disodium dodecaneLZ-dicarboxylic acid hydroxamate. 11 Disodium pentadecane-l,l-dicarboxylic acid hydroxamate.

Example The corrosion rates of each detergent powder in 0', 4 and 24 H w ter at four concentrations were determined using the same experimental technique as used in the previous examples. The results are shown below:

TABLE VII Corrosion rates for the powder 01 Example 8 Powder concentration TABLE VIII Corrosion rates for the powder of Example 9 Powder concentration Water hardness:

TABLE IX Corrosion rates for the powder of Example 10 Powder concentration Water hardness:

TABLE X Corrosion rates for the powder 01 Example 11 Powder concentration The detergent powders of Examples 8, 9 and 11 showed little tendency to corrode copper over a wide range of powder concentration and water hardness, and the detergent powder of Example 10 showed satisfactory corrosion-inhibiting properties at the lower powder concentrations at which it was tested, these concentrations being ones at which detergent powders are very commonly employed.

What is claimed is:

1. A detergent composition consisting essentially of:

(a) from about 1 to about 50% by weight of a detergent active agent selected from the group consisting of anionic, nonionic, cationic and amphotcric detergent active agents;

(b) from about 5 to about 50% by weight of an alkali-metal salt of nitrilotriacetic acid, said alkalimetal being selected from the group consisting of sodium and potassium;

(c) from about 5% to about 40% of a peroxy-compound selected from the group consisting of sodium perborate, potassium perborate and sodium percarbonate;

(d) from about 0.1 to about 20% (expressed by weight of the amount of said peroxy-compound present in said detergent composition) of a copper-copper alloy anti-corrosive agent consisting essentially of an alkali-metal salt selected from the group consisting of sodium and potassium salts of hydroxamic acids having-the structural formulae:

ONHOH Rj-CH-CHr-CONHOH ONHOH wherein R is selected from the group consisting of substantially straight-chain C C alkyl and monounsaturated alkenyl groups, and R is selected from the group consisting of substantially straight-chain C -C alkyl groups, said detergent compositions being inhibited with respect to the corrosion of copper and copper alloys.

2. A detergent composition according to claim 1,

wherein said alkali-metal salt of said hydroxamic acid is present in an amount of from about 0.25 to about 5% by weight of said peroxy-compound.

3. A detergent composition according to claim 1, wherein R is a C -C group and R is a C -C group. 4. A detergent composition according to claim 1, wherein said hydroxamic acid has the structural formula R CONHOH 5. A detergent composition according to claim 4, wherein said hydroxamic acid is derived from fatty acids derived from tallow-class fats.

6. A detergent composition according to claim 1 consisting essentially of:

(a) from about 5 to about 25% by weight of a detergent active agent selected from the group consisting of anionic, nonionic, cationic and amphoteric detergent active agents;

(b) from about 10 to about 40% by weight of the trisodium salt of nitrilotriacetic acid;

(c) from about 5 to about 40% by weight of a peroxycompound selected from the group consisting of sodium perborate, potassium perborate and sodium percarbonate;

(d) from about 0.25 to about 5% (expressed by weight of said peroxy-coinpound present in said detergent composition) of a sodium salt of a hydroxamic acid selected from the group consisting of hydroxamic acids having the structural formulae:

Rr-C ONHOH Rr-CH-C ONHOH ONHOH Rr-CH-CHz-C ONHOH ONHOH References Cited UNITED STATES PATENTS 11/1967 Zimmerer 252137 1/1956 Ruff 252137 OTHER REFERENCES Amino Acid Chelating Agents in Detergents, Soap and Chemical Specialties, September 1966, pp. 58-62, -135.

MAYER WEINBLA'I'I, Primary Examiner US. Cl. X.R.

252NTA Digest, 137, 152 

